list1=[]
list1.append(5)
list1.append(9)
list1.append(13)
# list1.insert(0,5)
# list1.insert(1,9)
# list1.insert(2,13)
list1.extend([5,9,13])
list2=["张飞","刘备","刘老二","曹操","关羽","刘邦"]
list2[2]="周瑜"





